The demystified ivermectin infertility study only had a sample of 37 people
Viral claims that the drug Ivermectin causes infertility in 85 percent of men were based on questionable findings from a 2011 study that included only 37 subjects.
Recent news articles and memes have argued infertility based on a 2011 study conducted in Nigeria. The study focused on ivermectin as a treatment for river blindness, a parasitic infection endemic to Africa and one of the conditions for which the drug is approved to treat in humans. However, infertility is not a known side effect of ivermectin, according to the Food and Drug Administration (FDA).
The infertility claim has spread rapidly due to the increasing use of ivermectin by some as an unapproved and possibly ineffective treatment for COVID-19. The 85 percent figure is not from the Nigerian study itself, but rather from a different study it refers to, although no record of the study could be found in the cited review. . The Nigerian study, which was conducted without a control group, also tested the possible effects of the drug on male fertility.
Of the 385 men initially included in the Nigerian study, data from only 37 were ultimately investigated, with the remaining men being excluded due to their already too low sperm count. Of the 37 men whose sperm count was high enough to be studied, it was found that their fertility was adversely affected, although the effect was small in some subjects, and it was not clear whether it was was a temporary effect.
There is little reason to believe that ivermectin causes infertility in humans. The Nigerian study was conducted on a small number of subjects, and questions were raised about the study methodology and the peer review process of the journal in which it was published. Some research has suggested that the drug has an impact on the fertility of farm animals. , but animal research often does not apply to humans.
There is also little reason to believe recent claims that ivermectin is a “cure” or useful treatment for COVID-19. While a number of small studies have suggested that ivermectin may have potential as a COVID-19 treatment, many other studies have shown no benefit or been inconclusive. Some of the studies that have shown positive results have been criticized by experts for poor design and other mistakes.
A large meta-analysis in July that was presented as evidence of ivermectin’s effectiveness against COVID-19 was quickly retracted when it was discovered that fraudulent data had been used. Without the fraudulent data, the analysis found that ivermectin had no impact on the survival of COVID-19 patients. Additional research is ongoing, but the available evidence does not support the claim that ivermectin is an effective treatment for COVID-19.
Although the drug is generally well tolerated when used for approved conditions and at appropriate doses, the FDA said last week that it had “received several reports of patients requiring medical attention, including hospitalization, after self-medicating with ivermectin intended for livestock. “
The FDA has warned consumers who may have an unfounded belief that ivermectin is a COVID-19 cure that the drug should not be used off-label because it can cause a host of unpleasant side effects outside of infertility, even if it does not come from veterinary medicine.
“Even ivermectin levels for approved human uses may interact with other drugs, such as blood thinners,” the FDA notice states. “You may also overdose ivermectin, which can cause nausea, vomiting, diarrhea, hypotension (low blood pressure), allergic reactions (itching and hives), dizziness, ataxia ( balance problems), seizures, coma and even death. “
News week contacted the FDA for comment.